| /******************************************************************************* |
| * Copyright (c) 2012, 2015 Oracle and/or its affiliates. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 |
| * which accompanies this distribution. |
| * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html |
| * and the Eclipse Distribution License is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| * |
| ******************************************************************************/ |
| package org.eclipse.persistence.jpa.jpql; |
| |
| import org.eclipse.persistence.jpa.jpql.parser.AbstractTraverseParentVisitor; |
| import org.eclipse.persistence.jpa.jpql.parser.BadExpression; |
| import org.eclipse.persistence.jpa.jpql.parser.CollectionExpression; |
| import org.eclipse.persistence.jpa.jpql.parser.DeleteClause; |
| import org.eclipse.persistence.jpa.jpql.parser.DeleteStatement; |
| import org.eclipse.persistence.jpa.jpql.parser.FromClause; |
| import org.eclipse.persistence.jpa.jpql.parser.IdentificationVariable; |
| import org.eclipse.persistence.jpa.jpql.parser.IdentificationVariableDeclaration; |
| import org.eclipse.persistence.jpa.jpql.parser.JPQLExpression; |
| import org.eclipse.persistence.jpa.jpql.parser.NullExpression; |
| import org.eclipse.persistence.jpa.jpql.parser.RangeVariableDeclaration; |
| import org.eclipse.persistence.jpa.jpql.parser.SelectStatement; |
| import org.eclipse.persistence.jpa.jpql.parser.UnknownExpression; |
| import org.eclipse.persistence.jpa.jpql.parser.UpdateClause; |
| import org.eclipse.persistence.jpa.jpql.parser.UpdateStatement; |
| |
| /** |
| * This visitor traverses the parsed tree and retrieves the {@link IdentificationVariable} |
| * defined in the base range variable declaration for the top-level statement if and only if the |
| * query is a <code><b>DELETE</b></code> or <code><b>UPDATE</b></code> query. |
| * |
| * @since 2.5 |
| * @version 2.5 |
| * @author Pascal Filion |
| */ |
| public class BaseDeclarationIdentificationVariableFinder extends AbstractTraverseParentVisitor { |
| |
| /** |
| * The {@link IdentificationVariable} used to define the abstract schema name from either the |
| * <b>UPDATE</b> or <b>DELETE</b> clause. |
| */ |
| public IdentificationVariable expression; |
| |
| /** |
| * Determines if the {@link RangeVariableDeclaration} should traverse its identification |
| * variable expression or simply visit the parent hierarchy. |
| */ |
| protected boolean traverse; |
| |
| /** |
| * Creates a new <code>BaseDeclarationIdentificationVariableFinder</code>. |
| */ |
| public BaseDeclarationIdentificationVariableFinder() { |
| super(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(BadExpression expression) { |
| // Incomplete/invalid query, stop here |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(CollectionExpression expression) { |
| if (traverse) { |
| // Invalid query, scan the first expression only |
| expression.getChild(0).accept(this); |
| } |
| else { |
| super.visit(expression); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(DeleteClause expression) { |
| try { |
| traverse = true; |
| expression.getRangeVariableDeclaration().accept(this); |
| } |
| finally { |
| traverse = false; |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(DeleteStatement expression) { |
| expression.getDeleteClause().accept(this); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(FromClause expression) { |
| if (traverse) { |
| expression.getDeclaration().accept(this); |
| } |
| else { |
| super.visit(expression); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(IdentificationVariable expression) { |
| if (traverse) { |
| this.expression = expression; |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(IdentificationVariableDeclaration expression) { |
| if (traverse) { |
| expression.getRangeVariableDeclaration().accept(this); |
| } |
| else { |
| super.visit(expression); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(JPQLExpression expression) { |
| expression.getQueryStatement().accept(this); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(NullExpression expression) { |
| // Incomplete/invalid query, stop here |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(RangeVariableDeclaration expression) { |
| if (traverse) { |
| expression.getIdentificationVariable().accept(this); |
| } |
| else { |
| super.visit(expression); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(SelectStatement expression) { |
| // Nothing to do because this visitor is only meant for DELETE or UPDATE queries |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(UnknownExpression expression) { |
| // Incomplete/invalid query, stop here |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(UpdateClause expression) { |
| try { |
| traverse = true; |
| expression.getRangeVariableDeclaration().accept(this); |
| } |
| finally { |
| traverse = false; |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void visit(UpdateStatement expression) { |
| expression.getUpdateClause().accept(this); |
| } |
| } |